#![allow(non_camel_case_types)]

use std::ffi::CStr;
use std::ptr;
use std::os::raw::c_void;
use std::mem;

fn check_error(e: *const u8) {
    if e.is_null() {
        println!("Not an error!");
        return;
    } else {
        unsafe {
            println!("{}", CStr::from_ptr(e as *const i8).to_str().unwrap());
        }
    }
}

struct rs2_error {
    #[allow(dead_code)]
    unused: [u8; 8],
}

fn rs2_create_context(error: *mut rs2_error) {
    unsafe {
        std::ptr::write(error, mem::transmute("my_error".as_ptr()));
    }
}

fn main() {
    let error: *mut u8 = ptr::null_mut();
    rs2_create_context(error as *mut rs2_error);
    check_error(error as *mut u8);
}